A queuing method for controlling congestion, in a S.N.A. network (systems network architecture) is described in I.E.E.E. Transactions on Communications, Vol. Com-30, No. 1, January 1982. The article is entitled "Performance Analysis of the S.N.A. Virtual Route Pacing Control" and is written by Mischa Schwartz. During high traffic intensity, when a central processor is receiving the greatest number of signals it manages to dispose of at a given program level, there is obtained in the prior art an overload of the associated memory buffers on a lower level, since work is being carried out all the time at one and the same (higher) level.